Complete trisomy 9 detected by noninvasive prenatal testing and confirmed by amniocentesis.

Complete chromosome 9 trisomy (T9) is a rare and fatal chromosomal disorder. We performed non-invasive prenatal testing (NIPT) in a patient with threatened abortion symptoms and found that the fetal was at risk for complete chromosome 9 trisomy. This shows that NIPT has certain accuracy in detecting trisomy of chromosome 9, which provide options for prenatal diagnosis of rare chromosomal abnormalities.